


All The Way Inside

by DirtyKnots



Series: Kinktober 2018 [10]
Category: Teen Wolf (TV)
Genre: Anal Sex, Established Relationship, Improvised Sex Toys, M/M, Macro/Micro, Rimming, VERY light bondage, extreme micro, full body anal insertion, magical mishaps, shrunken Derek
Language: English
Status: Completed
Published: 2018-10-10
Updated: 2018-10-10
Packaged: 2019-08-02 06:26:16
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,468
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16299833
Author URL: https://archiveofourown.org/users/DirtyKnots/pseuds/DirtyKnots
Summary: Teen Wolf Kink Bingo - Square 5: Improvised DildoKinktober 2018 - Day 10: Micro/MacroDerek is shrunk by a witch - that doesn't mean he and Stiles can't still have sex though.





	All The Way Inside

**Author's Note:**

> I don't even know how to tag this. Are there tags for this? WHO TF KNOWS? So, if you know of tags I should be using to warn for this, let me know I guess?

The spell was a minor frustration. Or, well, minor for Stiles. Major for Derek. He dealt with it like a champ though - letting the others take the lead in dealing with the witch, staying back even though it pained him to do so. Not like he could’ve helped anyhow - not with how he was. Shrinking spells didn’t have a whole lot of information space in any of the books they’d found, though at least there was some information. Mostly that it would wear off after a few days, a week at the outside. In the meantime, Derek was stuck at just over eight inches tall. The witch was dispatched fairly quickly at least. After that, it was just a matter of finding someone to take him home and keep an eye out - luckily he had someone who was more than happy to do that for him.

Figuring out how to feed a miniature werewolf was only a tiny challenge, Stiles eventually just telling Derek to take what he wanted off of Stiles’ plate and then filling up a water cap for him to drink from. He may or may not have gotten bit after making a joke about tiny dog bowls. Whatever, it was worth it. The worst part, really, was the damper this was putting on their sex life. It’s not like they couldn’t go for a few days without it, they had before out of necessity. It’s just that they didn’t like to, especially not when they were both in the same place.

Surprisingly, it was Derek who came up with the solution. Stiles’ wide-eyed ‘are you sure’ was met with firm insistence that, yes, Derek was. He missed being able to fill Stiles up and...well...technically he still could. Stiles, for his part, told Derek that he’d go ahead and try, but that Derek was definitely taking all of the lead on this one. He may be a werewolf, but that didn’t mean Stiles was willing to risk hurting him. Derek, of course, was fine with that. He watched as Stiles tied ropes to the base of their bed, scooted up and laid his ankles over the soft velcro cuffs.

“You don’t have to do this Stiles.” Derek could hear the elevated heartbeat, smell the slight tinge of worry.

“Yeah, Der, I do. If you want to do this, I’m all for it - hell I’m excited to try it - but this is the safest way.” He wasn’t lying, so Derek marched up the bed and did his best to tightly cinch Stiles’ ankles into place, leaving his legs spread wide without the ability to close. He took a minute to look his fill, not used to everything before him being so big (by comparison of course). He moved closer and heard the hitch in Stiles’ breath as he lost sight of Derek. Derek had to admit, he liked that he was basically invisible in this position. He gave himself a minute to reach forward and fondle Stiles’ balls, amazed at how big they were now, bigger than his head. He leaned forward and sucked on the loose skin, liking the gasp and tremor that came from Stiles at the new sensation.

“Move them out of the way, let me see.” He practically had to yell for Stiles to hear him over the harsh sounds of his own breath, but he was rewarded for the effort when Stiles’ hand came down and shifted his balls out of the way, baring his crack and hole. Derek did have to shift over quickly when Stiles, not able to see exactly where he was, dropped the tube of lube down right where Derek had been standing. It wouldn’t have done damage, he doesn’t think, but it would’ve been annoying to wait if it had. He retaliates for the oversight by letting his fangs drop and scraping them over the puckered skin around Stiles’ hole. He laughs at the shout it pulls from Stiles. The fangs go back in and Derek soothes the slightly roughened skin with his tongue, letting it drag over the ridges, enjoying how much more he can play now than normal. He’s able to lick between the puckered masses, rub his entire torso against Stiles’ rim. When he licks at Stiles’ hole, he can see up close just how easily it blooms open for him, and he can’t stop himself from rubbing his entire face in it, pushing his whole mouth inside for a brief moment. Stiles is gasping and squirming above him, and Derek can’t wait anymore.

The cap of the lube isn’t on tightly - which Derek is thankful for. He’s still strong enough to open it, but it would’ve been awkward and difficult to brace himself. Instead, it twists off smoothly and he tilts it until the viscous liquid is puddling out of it, reaching down to coat himself from foot to shoulders with it. He’d lost his clothes when he’d been shrunk, and had been naked since, it was definitely working in his favor at the moment. His own cock is hard and leaking, but he ignores it for now as he shifts forward again and begins pushing his hands - now the size of a Ken doll’s - into Stiles’ hole. It doesn’t take long at all until he’s got both in, working around the rim, coating it with lube and gently tugging to stretch him. It takes even less time before he’s able to shift around, putting first one leg and then the other inside of Stiles completely. When he’s done as much as he can on his own, he finally calls up to Stiles again.

“Okay, it’s your turn.”

“Der - are you sure, really?” Stiles’ breathing is ragged, and Derek can feel the slightest contractions of the muscles in his ass as he fights not to clench down. It’s nearly overwhelming, being so surrounded by Stiles’ scent, by his body.

“Yeah, yeah I’m sure.”

“Kay.” Stiles’ hand is gentle when it comes down to brush against him before his fingers wrap around Derek’s body. Derek gasps when Stiles uses his grip to push Derek inside of him further - thumb sweeping to make sure he stops before Derek’s neck goes in. It’s even more overwhelming like this and Derek has to fight the urge to tell Stiles to push him in all the way, to smother him inside of his ass. He doesn’t think Stiles would, if he’s honest, and the thought is a little disappointing. He’d survive it, after all. Instead he does his best to remain mostly rigid as Stiles pulls him out a bit and pushes him back in. It works for a bit, but Derek was never one to remain too passive, and soon he’s moving his body every time he’s encased up to his shoulders - sliding his legs up and down, rubbing his hands and arms over Stiles’ inner walls. He can feel the way it makes Stiles shake and writhe, the velcro on his ankles the only thing preventing him from snapping his legs closed to ride Derek’s body harder. The heat and wet of being inside of Stiles is getting to Derek too, and soon enough he’s nipping at Stiles’ fingers to make him stop trying to pull him back out, feet pressed hard against Stiles’ prostate, undulating, as he shifts his hands to jack his own cock, knowing Stiles can feel each movement inside of him.

Derek can feel the way Stiles is fighting his own urges to clench, his inner walls tightening and releasing rapidly, the pressure just enough of a threat to make Derek finally shoot off, emptying his balls inside of Stiles. He wriggles in a little further, until his face is pushed against Stiles’ rim, and then he starts licking and sucking it, kissing like it’s Stiles’ mouth, continuing the press and release against Stiles’ prostate with his feet. He loses his breath when Stiles finally comes, his body clamping down hard as he spills, and Derek thinks maybe he blacks out for a second as his chest is compressed. He’d felt this on his cock before, but it was never quite like this. He likes it more than he thinks he should admit. His shoulders slip free of Stiles’ rim when he finally finishes coming, body going lax, but instead of pulling himself free, he simply slips his arms out, taking care to pet at Stiles’ hole. He’s warm, surrounded by one of his favorite scents - made better for how he can smell himself here too now, more fully than ever before even - and when Stiles’ hand comes to free him, he snaps at it.

“Fine Der, stay there all night then.” Stiles huffs it out but there’s no real bite. Derek though, he plans to do just that.

**Author's Note:**

> Come find me on [DreamWidth](https://dirtyknots.dreamwidth.org/), all of my additional contact information can be found there or on my [Profile Page](https://archiveofourown.org/users/DirtyKnots/profile) here (including where you can leave me prompts of your own)!


End file.
